SPDSS_Task7-2_WellUseWellAugmentationPlans

Development of a database using the 2001 well acreage within the designated basins, decreed alternate point wells, Coffin wells, and the HydroBase augmentation plan associations resulted in the distribution of well acreage in the SPDSS study area summarized in Table 2. Table 2 Summary of Wells and Well Acreage in SPDSS Study Area Type # of Wells Well Acreage % of Well Acreage Designated Basins 724 56,374 14.04% Coffin Wells 419 16,515 4.11% Decreed alternate point wells 21 1,631 0.41% Wells Requiring Augmentation 4,977 326,909 81.44% TOTAL 6,141 401,429 100.00% Source: SPDSS 2001 GIS Irrigated Acreage Assessment (June 19, 2007), associated GIS coverages, and HydroBase ~V20060816). Notes: Based on match of WDID of wells in irrigated acreage coverage to Receipt number of wells geographically within designated basins (see Figure 1). Some decreed alternate point wells are also included in augmentation plans, based on HydroBase associations. Characterization of the well types in Table 2 is discussed further below and in the Approach section. Recommendations for representation of these wells in the SPDSS model are discussed in the Modeling Recommendations and Plan Operations section. Designated Basin Wells Wells within the designated basins were identified based on match of WDID of wells in the irrigated acreage coverage to the Receipt Number of wells geographically within designated basins (see Figure 1). A total of 56,374 acres are associated with the 724 designated basin well IDs, as summarized in Table 2. Coffin Wells Coffin wells were decreed as non-tributary in Civil Action 11217. A total of 16,515 acres are associated with the 419 Coffin well IDs, as summarized in Table 2. Decreed alternate point wells The surface water rights for the following ditches in the lower South Platte River basin were decreed to alternate point wells. In some cases, this was due to ditch headgates washed out in floods or otherwise becoming unusable. A total of 1,631 acres are associated with the 21 alternate point well IDs, as summarized in Table 3: Table 3 Summary of Decreed Alternate Point Wells in the SPDSS Study Area Surface Water ffi ht WDID # of Wells Well Acrea e Hoover Ditch 0100500 12 335 Carlson Ditch 6400501 No wells, just pumps in the river Tamarack Ditch 6400509 2 553 Jud Brush Ditch 6400519 2 214 Sterling Irrigation Company Ditch No. 2 6400526 5 529 Sterling Herford Cattle Company Ditch 6400527 No wells or pumps TOTAL 21 1,631 Source: SPDSS 2001 GIS Irrigated Acreage Assessment (June 19, 2007), DWR straightline diagrams, HydroBase (V20060816), APOD database, and Division 1 personnel. 8of16